{{"key":"k1","value":"v1"},
{"key":"k2","value":"v2"},
{"key":"k3","value":"v3"},
{"key":"k4","value":"v4"}}

{{"key":"k1","value":["v1","v2","v3"]},
{"key":"k2","value":["v4","v5","v6"]},
{"key":"k3","value":["v7","v8","v9"]}}